Sear mechanism



Feb, 22, 1949. v WESSON I 2,462,535

SEAR MECHANISM Filed Aug. 51, 1945 Patented Feb. 22, 1949 UNE- SEAR MECHANISM Appiication August 31, 1945, Serial No. 613,928

14 Claims.

.pull, particularly with respect to small arms,

tends to interfere with accuracy of fire.

A principal object of the present invention is toprovide novel sear mechanism capable of holding the hammer in cocked position without danger of accidental release but which may be actuated to release the hammer for firing by a very slight trigger pull. A further object is to provide sear mechanism which is reliable, durable, simple and inexpensive and which is not adversely affected by moisture, grit or other conditions incident to use.

A further object is to provide sear mechanism capable of holding the hammer in any desired position of cock, that is to say, anywhere between firing position and full cock, but which releases the hammer in response to trigger pull, with substantially equal ease and certainty, from any of said cocked positions. Other and further objects and advantages of the invention will be pointed out in the following more detailed description and by reference to the accompanying drawings, wherein Fig. 1 is a fragmentary side elevation of a revolver with a portion of the grip removed to show the interior mechanism, the hammer being shown in firing position;

Fig. 2 is a fragmentary view, generally similar to Fig. 1, but showing the hammer in full cocked position;

Fig. 3 is a fragmentary detail elevation, to larger scale than Fig. 1, showing the lower portion of the hammer together with the sear mechanism, the hammer being in the firing positien; and

Fig. 4 is a fragmentary section substantially on the line dfi of Fig. 3.

Referring to the drawings, the numeral i designates the frame of a revolver of a generally conventional type having the barrel 2, the trigger guard 3 and the grip portion 6. The hammer 5 is pivoted at b and is provided with the actuating spring 5 connected at its free end to a link? which is pivotally connected at 8 to a rearwardly directear on the hammer and at a point in a plane below the axis 'of the pivot 6.

2 usual type (not here shown) but which is not necessary when the sear mechanism of the present invention is employed.

The hammer is provided with a downwardly directed tail portion ll having an arcuate lower face 12 which is preferably concentric with the axis of the hammer pivot 6.

The sear mechanism, which is spaced below the arcuate surface [2, comprises a rigid abutment l3 which may be formed as an integral boss at the inside of the frame, and which has a substantially fiat rectilinear upper surface I4 (Fig. 3). This surface It is preferably inclined downwardly and rearwardly so as to make an included angle less than with that radius l5 of the surface l2 which passes through the lower front corner iii of the tail member H of the hammer when the hammer is in firing position. This guide surface i i, together with the forward portion of the arcuate face l2, defines a recess open in front and which converges rearwardly. The sear, proper, consists of a wedge member [8, here shown as a cylindrical roll, which is disposed at the entrance to this recess I! when the hammer is in the firing position, the element l8 resting upon the guide surface i i and being limited as to endwise movement by the frame and the rear portion of the trigger. Preferably, as here illustrated, a follower member l9, having a concave rear surface which engages the peripheral surface of the roll i8, is guided by means of a rigid stem 26 sliding in a boss in a lug or car 2| projecting from the frame, so as to move in a path substantially parallel to the surface ill of the abutment iii. The sear mechanism also includes spring 22, surrounding the stem 20 and interposed between the follower i9 and the lug 2 l, and which urges the follower l9 rearwardly and thus tends to force the roller 18 rearwardly along the recess The trigger 9 is provided with an upwardly and rearwardly extending arm 23 (Figs. 3 and 4) pro vided with a transversely extending finger 24 (Fig. 4) which lies immediately behind the roll l8.

When the hammer is drawn backwardly to cook the gun, the arcuate face l2 of the tail ll of the hammer swings forwardly in contact with the peripheral surface of the sear roll l8 and may turn the roll 58 in so doing. The spring 22 tends constantly to push the roll l8 rearwardly into the converging recess ll and as soon as the cocking force upon the hammer ceases, the roll acts as a wedge or clutch element, reacting between the converging surfaces I l and face 12, thus holding the hammer in cocked position. This action of the roll 18 takes place in substantially the same manner Whether the hammer be drawn back to full cocked position or to any intermediate position, it being noted that the frictional engagement of the surface I2 with the periphery of the roll [8 tends to roll the element I8 rearwardly into the recess in response to the slightest movement of the hammer by the spring S, so that even Without the spring 22 the clutch element l8 would still act to hold the hammer in cocked position, the spring 22 merely assuring that the roll i8 will be in readiness to perform its clutching action.

Since the face I2 is coaxial with the pivotal axis 6 of the hammer, the slightest separation of the face I2 from the periphery of the roll 18 instantly permits the hammer to move forward without restriction to the firing position. When the hammer has been drawn back to cocked position, a very light pull on the trigger moves the clutch roll [8 forwardly, thus releasing the hammer.

While a cylindrical roll I8 is desirable, it is contemplated that a ball may likewise be employed with suitable provision for guiding and retaining it, and likewise that a wedge member of other than roller type may be used if desired.

While one desirable embodiment of the invention is herein illustrated by way of example, it is to be understood that the invention is broadly inclusive of any and all modifications falling within the scope of the appended claims.

What is claimed is:

1. A firearm having in combination a spring pivoted hammer, a pivoted trigger and means for holding the hammer in cocked position, said holding means including a roller clutch element, engageable with a surface of the hammer, and spring means urging the clutch element toward operative position, and trigger-actuated means for moving the clutch element to inoperative position.

2. A firearm having in combination a springactuated pivoted hammer, a pivoted trigger and a sear mechanism for holding the hammer in cocked position, the hammer having a tail portion provided with an arcuate surface, the sear .mechanism comprising a roller clutch element engageable with said arcuate surface of the hammer, a rigid abutment and a spring tending to ad vance the clutch element between the abutment and the arcuate surface of the hammer thereby to hold the hammer in cocked position, and trigger-actuated means for retracting the clutch element.

3. A firearm having in combination a springactuated pivoted hammer, a trigger, and sear mechanism for holding the hammer in cocked position, the hammer and the sear mechanism being so constructed and arranged as to hold the hammer at any degree of cock, and means actuable by the trigger for actuating the sear mechanism thereby to release the hammer from any cocked position.

4. A firearm having in combination a springactuated pivoted hammer, a trigger, a roller clutch device operative to hold the hammer at any degree of cock, and trigger-actuated means for releasing the hammer from any cocked position.

5. A firearm having in combination a springactuated pivoted hammer and a pivoted trigger,

' a roller clutch element, a rigid guide for said element, and a spring tending to move the clutch element along the guide into a position such as bywedge action to hold the hammer in cocked position, the hammer having a tail piece engageable by said clutch element, and trigger-actuated means for moving the clutch element in opposition to its actuating spring.

6. A firearm having in combination a springactuated pivoted hammer and a pivoted trigger, the hammer having an arcuate end face concentric with the pivotal axis of the hammer, a rigid abutment having a substantially fiat guide surface spaced from the arcuate face of the hammer, and which, together with said arcuate face, defines a recess open at its front end and converging rearwardly, a clutch roller normally disposed at the entrance of said recess, a spring tending to move the clutch element rearwardly into the recess thereby to act as a wedge to hold the hammer in cocked position, and a part carried by the trigger and engageable with the clutch element to move the latter toward the end of the recess.

7. A firearm having in combination a springactuated pivoted hammer and a pivoted trigger, the hammer having an arcuate end face concentric with the pivotal axis of the hammer, a wedge element movable in one direction for operative engagement with said arcuate face in any position of cock of the hammer thereby to retain the hammer in any such position, and triggeractuable means for moving the wedge element in the other direction to inoperative position.

8. A firearm having in combination a springactuated pivoted hammer and a pivoted trigger, the hammer having an arcuate end face concentric with the pivotal axis of the hammer, a rigid abutment having a substantially rectilinear guide surface spaced from the arcuate face of the hammer and making an included angle of less than with that radius of the arcuate surface which defines the forward end of said arcuate surface when the hammer is in the firing position, a roller movable along said guide surface into the angle between the latter and the arcuate face of the hammer, a spring-pressed follower engaging the roller and tending to move the latter into said angle thereby to hold the hammer cocked, and trigger-actuated means for moving the roller toward the forward end of the recess thereby to release the hammer.

9. A firearm having in combination a springactuated pivoted hammer and a trigger, the hammer having a tail portion provided with an edge face, a fixed abutment spaced from the edge face of the tail portion of the hammer, a wedge element designed to be advanced into an operative position between said abutment and the edge face of the hammer thereby to hold the hammer cooked, and trigger-actuated means for retracting the wedge member to an inoperative position.

10. A firearm of the kind having in combination a spring-actuated pivoted hammer and a trigger, the hammer having a tail portion provided with an arcuate end surface, a fixed abutment spaced from said arcuate surface and which is in a plane parallel to the pivtol axis of the hammer, a wedge member designed to be advanced to an operative position between said arcuate surface and the abutment thereby to hold the hammer in cocked position, and trigger-actuated means for retracting the wedge member to an inoperative position.

11. A firearm having in combination a springactuated pivoted hammer and a trigger, the hammer having a tail portion providing an arcuate end face, a fixed abutment spaced from and having a surface which is in a plane parallel to the pivotal axis of the hammer, a rotary clutch element designed to roll along said surface of the abutment and to become wedged between the latter and the arcuate surface of the hammer, thereby to hold the hammer in cocked position, and trigger-actuated means for moving the clutch element to inoperative position.

12. A firearm having in combination a springactuated pivoted hammer and a trigger, the hammer having a tail portion provided with an arcuate end face concentric with the pivotal axis of the hammer, a rigid abutment having a guide surface which, in cooperation with the forward portion of said arcuate face, defines a recess which is convergent rearwardly, a clutch element designed to be arranged to move along said guide surface, spring means tending to move the guide element toward the narrow end of the recess, and trigger-actuated means for moving the clutch element toward the wider end of the recess.

13. A firearm having in combination a springactuated pivoted hammer and a trigger, the hammer having a tail portion provided with an arcuate end face concentric with the pivotal axis of the hammer, a rigid abutment having a guide surface which, in cooperation with the forward portion of said arcuate face of the hammer, defines a recess convergent rearwardly, a clutch element aranged to move along said guide surface toward the narrower end of the recess and which by a wedge action holds the hammer in cocked position, and a trigger-actuated part for moving the clutch element toward the wider end of the recess thereby to release the hammer.

14. A firearm having in combination a springactuated pivoted hammer and a trigger, the hammer having a tail portion provided with an arcuate end face concentric with the pivotal axis of the hammer, a rigid abutment having a substantially rectilinear guide surface which, in cooperation with a portion of the arcuate face of the hammer, defines a recess which is convergent rearwardly, a clutch roll arranged to roll along said guide surface, a follower engageable with said clutch roll, a guide for the follower for guiding it in a path substantially parallel to the guide surface of the abutment, a spring urging said follower toward the narrow end of the recess, and a part carried by the trigger and engageable with the rear surface of the clutch roll for moving the latter forwardly in opposition to said spring.

SPRINGFIELD SAFE DEPOSIT AND TRUST COMPANY, Executor of the Last Will and Testament of Victor H. Wesson, Deceased. By EUGENE W. SHAW,

Its Trust Officer.

No references cited. 

